Annotation of libelwix/src/ring.c, revision 1.4.4.1
1.2 misho 1: /*************************************************************************
2: * (C) 2025 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
3: * by Michael Pounov <misho@elwix.org>
4: *
5: * $Author: misho $
1.4.4.1 ! misho 6: * $Id: ring.c,v 1.4 2025/09/30 11:38:28 misho Exp $
1.2 misho 7: *
8: **************************************************************************
9: The ELWIX and AITNET software is distributed under the following
10: terms:
11:
12: All of the documentation and software included in the ELWIX and AITNET
13: Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
14:
1.4.4.1 ! misho 15: Copyright 2004 - 2026
1.2 misho 16: by Michael Pounov <misho@elwix.org>. All rights reserved.
17:
18: Redistribution and use in source and binary forms, with or without
19: modification, are permitted provided that the following conditions
20: are met:
21: 1. Redistributions of source code must retain the above copyright
22: notice, this list of conditions and the following disclaimer.
23: 2. Redistributions in binary form must reproduce the above copyright
24: notice, this list of conditions and the following disclaimer in the
25: documentation and/or other materials provided with the distribution.
26: 3. All advertising materials mentioning features or use of this software
27: must display the following acknowledgement:
28: This product includes software developed by Michael Pounov <misho@elwix.org>
29: ELWIX - Embedded LightWeight unIX and its contributors.
30: 4. Neither the name of AITNET nor the names of its contributors
31: may be used to endorse or promote products derived from this software
32: without specific prior written permission.
33:
34: THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
35: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37: ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38: FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39: DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40: OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42: LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43: OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44: SUCH DAMAGE.
45: */
46: #include "global.h"
47:
48:
49: /*
50: * rbuf_init() - Init ring buffer
51: *
52: * @rbuf = Ring buffer
53: * @num = Number of elements in buffer
54: * return: -1 error or 0 ok
55: */
56: int
57: rbuf_init(ringbuf_t *rbuf, int num)
58: {
59: if (!rbuf)
60: return -1;
61:
1.3 misho 62: atomic_store_explicit((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
63: atomic_store_explicit((atomic_int*) &rbuf->rb_tail, 0, memory_order_relaxed);
1.2 misho 64:
65: rbuf->rb_buffer = e_calloc(num, sizeof(struct iovec));
66: if (!rbuf->rb_buffer)
67: return -1;
68: else
69: rbuf->rb_bufnum = num;
70: memset(rbuf->rb_buffer, 0, num * sizeof(struct iovec));
71:
72: return 0;
73: }
74:
75: /*
76: * rbuf_free() - Free ring buffer
77: *
78: * @rbuf = Ring buffer
79: * return: none
80: */
81: void
82: rbuf_free(ringbuf_t *rbuf)
83: {
84: if (!rbuf)
85: return;
86:
87: if (rbuf->rb_buffer) {
88: e_free(rbuf->rb_buffer);
89: rbuf->rb_buffer = NULL;
90: rbuf->rb_bufnum = 0;
91: }
92:
1.3 misho 93: atomic_store_explicit((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
94: atomic_store_explicit((atomic_int*) &rbuf->rb_tail, 0, memory_order_relaxed);
1.2 misho 95: }
96:
97: /*
98: * rbuf_purge() - Purge all buffer
99: *
100: * @rbuf = Ring buffer
101: * return: none
102: */
103: void
104: rbuf_purge(ringbuf_t *rbuf)
105: {
106: if (!rbuf)
107: return;
108:
109: if (rbuf->rb_buffer)
110: memset(rbuf->rb_buffer, 0, rbuf->rb_bufnum * sizeof(struct iovec));
111:
1.3 misho 112: atomic_store_explicit((atomic_int*) &rbuf->rb_head, 0, memory_order_relaxed);
113: atomic_store_explicit((atomic_int*) &rbuf->rb_tail, 0, memory_order_relaxed);
1.2 misho 114: }
115:
116: /*
117: * rbuf_isempty() - Check buffer is empty
118: *
119: * @rbuf = Ring buffer
120: * return: -1 error, 0 it isn't empty
121: */
122: int
123: rbuf_isempty(ringbuf_t *rbuf)
124: {
125: if (!rbuf)
126: return -1;
127:
1.3 misho 128: return (atomic_load_explicit((atomic_int*) &rbuf->rb_head, memory_order_acquire) ==
129: atomic_load_explicit((atomic_int*) &rbuf->rb_tail, memory_order_acquire));
1.2 misho 130: }
131:
132: /*
133: * rbuf_isfull() - Check buffer is full
134: *
135: * @rbuf = Ring buffer
136: * return: -1 error or 0 it isn't full
137: */
138: int
139: rbuf_isfull(ringbuf_t *rbuf)
140: {
1.4.4.1 ! misho 141: int h, t;
! 142:
1.2 misho 143: if (!rbuf)
144: return -1;
145: if (!rbuf->rb_bufnum)
146: return 1;
147:
1.4.4.1 ! misho 148: t = atomic_load_explicit((atomic_int*) &rbuf->rb_tail, memory_order_acquire);
! 149: h = atomic_load_explicit((atomic_int*) &rbuf->rb_head, memory_order_relaxed) + 1;
! 150: if (h >= rbuf->rb_bufnum)
! 151: h ^= h;
! 152:
! 153: return (h == t);
1.2 misho 154: }
155:
156: /*
157: * rbuf_enqueue() - Enqueue data to buffer
158: *
159: * @rbuf = Ring buffer
160: * @data = Data
161: * @len = Length
162: * return: -1 error, 1 buffer is full or 0 ok
163: */
164: int
165: rbuf_enqueue(ringbuf_t *rbuf, void *data, size_t len)
166: {
167: int h, t, n;
168: struct iovec *iov;
169:
170: if (!rbuf || !rbuf->rb_buffer)
171: return -1;
172: if (!rbuf->rb_bufnum)
173: return 1;
174:
1.3 misho 175: h = atomic_load_explicit((atomic_int*) &rbuf->rb_head, memory_order_relaxed);
176: t = atomic_load_explicit((atomic_int*) &rbuf->rb_tail, memory_order_acquire);
1.2 misho 177: n = (h + 1) % rbuf->rb_bufnum;
178:
179: if (n == t)
180: return 1;
181:
182: iov = rbuf->rb_buffer + h;
183: iov->iov_len = len;
184: iov->iov_base = data;
185:
1.3 misho 186: atomic_store_explicit((atomic_int*) &rbuf->rb_head, n, memory_order_release);
1.2 misho 187: return 0;
188: }
189:
190: /*
191: * rbuf_dequeue() - Dequeue data from buffer
192: *
193: * @rbuf = Ring buffer
194: * @out = Data, if =NULL, just dequeue data
195: * return: -1 error, 1 buffer is empty or 0 ok
196: */
197: int
1.4 misho 198: rbuf_dequeue(ringbuf_t *rbuf, struct iovec **out)
1.2 misho 199: {
200: int h, t, n;
201:
202: if (!rbuf || !rbuf->rb_buffer)
203: return -1;
204: if (!rbuf->rb_bufnum)
205: return 1;
206:
1.3 misho 207: h = atomic_load_explicit((atomic_int*) &rbuf->rb_head, memory_order_acquire);
208: t = atomic_load_explicit((atomic_int*) &rbuf->rb_tail, memory_order_relaxed);
1.2 misho 209: n = (t + 1) % rbuf->rb_bufnum;
210:
211: if (h == t)
212: return 1;
213:
214: if (out)
1.4 misho 215: *out = rbuf->rb_buffer + t;
1.2 misho 216:
1.3 misho 217: atomic_store_explicit((atomic_int*) &rbuf->rb_tail, n, memory_order_release);
1.2 misho 218: return 0;
219: }
1.4.4.1 ! misho 220:
! 221:
! 222: /*
! 223: * lrb_init() - Init linear ring buffer
! 224: *
! 225: * @lrb = Linear ring buffer
! 226: * @size = Size of ring buffer
! 227: * return: -1 error or 0 ok
! 228: */
! 229: int
! 230: lrb_init(lrbuf_t *lrb, u_int size)
! 231: {
! 232: if (!lrb)
! 233: return -1;
! 234:
! 235: atomic_store_explicit((atomic_int*) &lrb->lrb_head, 0, memory_order_relaxed);
! 236: atomic_store_explicit((atomic_int*) &lrb->lrb_tail, 0, memory_order_relaxed);
! 237:
! 238: lrb->lrb_data = e_malloc(size);
! 239: if (!lrb->lrb_data)
! 240: return -1;
! 241: else
! 242: lrb->lrb_size = size;
! 243: memset(lrb->lrb_data, 0, lrb->lrb_size);
! 244:
! 245: return 0;
! 246: }
! 247:
! 248: /*
! 249: * lrb_free() - Free linear ring buffer
! 250: *
! 251: * @lrb = Linear ring buffer
! 252: * return: none
! 253: */
! 254: void
! 255: lrb_free(lrbuf_t *lrb)
! 256: {
! 257: if (!lrb)
! 258: return;
! 259:
! 260: if (lrb->lrb_data) {
! 261: e_free(lrb->lrb_data);
! 262: lrb->lrb_data = NULL;
! 263: lrb->lrb_size = 0;
! 264: }
! 265:
! 266: atomic_store_explicit((atomic_int*) &lrb->lrb_head, 0, memory_order_relaxed);
! 267: atomic_store_explicit((atomic_int*) &lrb->lrb_tail, 0, memory_order_relaxed);
! 268: }
! 269:
! 270: /*
! 271: * lrb_purge() - Purge all buffer
! 272: *
! 273: * @lrb = Linear ring buffer
! 274: * return: none
! 275: */
! 276: void
! 277: lrb_purge(lrbuf_t *lrb)
! 278: {
! 279: if (!lrb)
! 280: return;
! 281:
! 282: if (lrb->lrb_data)
! 283: memset(lrb->lrb_data, 0, lrb->lrb_size);
! 284:
! 285: atomic_store_explicit((atomic_int*) &lrb->lrb_head, 0, memory_order_relaxed);
! 286: atomic_store_explicit((atomic_int*) &lrb->lrb_tail, 0, memory_order_relaxed);
! 287: }
! 288:
! 289: /*
! 290: * lrb_isempty() - Check buffer is empty
! 291: *
! 292: * @lrb = Linear ring buffer
! 293: * return: -1 error, 0 it isn't empty
! 294: */
! 295: int
! 296: lrb_isempty(lrbuf_t *lrb)
! 297: {
! 298: if (!lrb)
! 299: return -1;
! 300:
! 301: return (atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire) ==
! 302: atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire));
! 303: }
! 304:
! 305: /*
! 306: * lrb_isfull() - Check buffer is full
! 307: *
! 308: * @lrb = Linear ring buffer
! 309: * return: -1 error or 0 it isn't full
! 310: */
! 311: int
! 312: lrb_isfull(lrbuf_t *lrb)
! 313: {
! 314: int h, t;
! 315:
! 316: if (!lrb)
! 317: return -1;
! 318: if (!lrb->lrb_size)
! 319: return 1;
! 320:
! 321: t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
! 322: h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_relaxed) + 1;
! 323: if (h >= lrb->lrb_size)
! 324: h ^= h;
! 325:
! 326: return (h == t);
! 327: }
! 328:
! 329: /*
! 330: * lrb_enqueue() - Enqueue data to buffer
! 331: *
! 332: * @lrb = Linear ring buffer
! 333: * @data = Data
! 334: * @len = Length
! 335: * @lost = Permit to lost data
! 336: * return: -1 error, 1 buffer is full or 0 ok
! 337: */
! 338: int
! 339: lrb_enqueue(lrbuf_t *lrb, void *data, size_t len, int lost)
! 340: {
! 341: int h, t, n, t2, unused, drop = 0;
! 342:
! 343: if (!lrb || !lrb->lrb_data)
! 344: return -1;
! 345: if (!lrb->lrb_size || lrb->lrb_size <= len)
! 346: return 1;
! 347:
! 348: lrb_unused(lrb, unused);
! 349: if (!lost) {
! 350: if (len > unused)
! 351: return 1;
! 352: } else {
! 353: drop = len - unused;
! 354: if(drop < 0)
! 355: drop ^= drop;
! 356: }
! 357:
! 358: if (drop > 0) {
! 359: t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
! 360: t2 = (t + drop) % lrb->lrb_size;
! 361: }
! 362: h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_relaxed);
! 363: n = lrb->lrb_size - h;
! 364: if (len < n) {
! 365: memcpy(lrb->lrb_data + h, data, len);
! 366: n = h + len;
! 367: } else {
! 368: memcpy(lrb->lrb_data + h, data, n);
! 369: memcpy(lrb->lrb_data, data + n, len - n);
! 370: n = len - n;
! 371: }
! 372:
! 373: atomic_store_explicit((atomic_int*) &lrb->lrb_head, n, memory_order_release);
! 374: if (drop > 0)
! 375: while (42) {
! 376: n = t;
! 377: if (atomic_compare_exchange_weak_explicit((atomic_int*) &lrb->lrb_tail,
! 378: &n, t2, memory_order_release, memory_order_relaxed))
! 379: break;
! 380: t = n;
! 381: t2 = (t + drop) % lrb->lrb_size;
! 382: }
! 383: return 0;
! 384: }
! 385:
! 386: /*
! 387: * lrb_dequeue() - Dequeue data from buffer
! 388: *
! 389: * @lrb = Linear ring buffer
! 390: * @data = Data, if =NULL, just dequeue data
! 391: * @len = Length of data
! 392: * return: -1 error, 0 buffer is empty or >0 stored data bytes
! 393: */
! 394: int
! 395: lrb_dequeue(lrbuf_t *lrb, void *data, size_t len)
! 396: {
! 397: int h, t, t2, n, l;
! 398:
! 399: if (!lrb)
! 400: return -1;
! 401: if (!lrb->lrb_size || !len || lrb_isempty(lrb))
! 402: return 0;
! 403: if (lrb->lrb_size <= len)
! 404: len = lrb->lrb_size - 1;
! 405:
! 406: while (42) {
! 407: t = atomic_load_explicit((atomic_int*) &lrb->lrb_tail, memory_order_acquire);
! 408: h = atomic_load_explicit((atomic_int*) &lrb->lrb_head, memory_order_acquire);
! 409:
! 410: l = h - t;
! 411: if (l < 0)
! 412: l += lrb->lrb_size;
! 413: if (!l)
! 414: return 0;
! 415: if (l > len)
! 416: l = len;
! 417:
! 418: n = lrb->lrb_size - t;
! 419: if (l < n) {
! 420: if (data)
! 421: memcpy(data, lrb->lrb_data + t, l);
! 422: t2 = t + l;
! 423: } else {
! 424: if (data) {
! 425: memcpy(data, lrb->lrb_data + t, n);
! 426: memcpy(data + n, lrb->lrb_data, l - n);
! 427: }
! 428: t2 = l - n;
! 429: }
! 430:
! 431: n = t;
! 432: if (atomic_compare_exchange_weak_explicit((atomic_int*) &lrb->lrb_tail,
! 433: &n, t2, memory_order_release, memory_order_relaxed))
! 434: return l;
! 435: }
! 436:
! 437: return 0;
! 438: }
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